


Trajectory

by weakinteraction



Category: Let It Roar - Battle Beast (Song)
Genre: F/F, Outrageous Cosmological Speculations, Transhumanism, Xenobiology
Language: English
Status: Completed
Published: 2017-06-02
Updated: 2017-06-02
Packaged: 2018-11-07 23:15:08
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,116
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11069097
Author URL: https://archiveofourown.org/users/weakinteraction/pseuds/weakinteraction
Summary: The designer of the first faster-than-light drive searches for her lover, the missing test pilot from its inaugural flight, and finds more than she had ever imagined.





	Trajectory

**Author's Note:**

  * For [ExtraPenguin](https://archiveofourown.org/users/ExtraPenguin/gifts).



_Planet X_  
_Transcriptions: 153_

Ammonia crystals crunched beneath Vikk's feet as she stepped out of the descent pod on to the surface of the planet. Methane winds howled around her in a permanent maelstrom; the planet was tidally locked to its dim parent star, and while the twilight region stretching around the planet seemed to have the right temperature range for the local life forms, the endless flow of air from the day side to the great vortex in the centre of the night side hardly made for a hospitable environment. From orbit, Vikk had amused herself by imagining how Alanna would have seen it: she would probably have imagined taking a glider across the planet, riding the great currents before descending into the perpetual storm. Down on the surface, though, the force of the wind would have been nearly enough to knock her off her feet, just as it was now threatening to do to Vikk.

Interface had insisted on labelling this as Planet X, following a scheme that had long outgrown its usefulness. It had been twenty-three transcriptions since Planet W, the last planet with signs of life -- ultimately turning out just to be single-celled algae in a planetwide ocean, much as Earth had been for three quarters of its history.

Vikk looked around. There was no obvious sign of any life form here. The analysis from orbit had shown high levels of probable metabolic by-products in this region, but it seemed very likely that any creatures that might be here were underground.

Wait. There was some sort of motion up ahead. Vikk struggled on through the wind to a small outcropping of rock -- almost 100% aluminosilicate, according to a spectroscopic analysis Interface flashed up on the HUD momentarily, though with a slew of anomaly symbols. In the tiny amount of shelter offered by the leeside of the rock, some small green-black creatures were burrowing their way out of the ice. Vikk hurried over to see. Had they emerged because she was here? If they were sensitive to vibration in some way, the bumpy landing of the descent pod would have been more than enough to trigger activity.

She stretched out a gloved hand, patiently waiting for one of the creatures to crawl on to it. She brought it up to her face, Interface reading her intentions before they were fully formed and adjusting the refractive properties of the lower part of the helmet to act as a magnifier. Interface would be running its own analysis, and uploading data to its sibling processes on the ship for them to work on, although the activity report from on board -- usually a quiescent blue in its heatmap, with occasional green glows where essential systems maintained their awareness, with a single spark of red indicating the routines managing the Engine's dynamic equilibrium -- was now flaring red and white across the board, showing that the composition of the rock itself was occupying a surprising amount of their attention. But Interface knew that Vikk liked to discover things for herself, and so gave her the opportunity to observe the creature up close, as unmediated as possible.

Overall, it was about the size of her middle finger, and had sixfold radial symmetry. At what she assumed was the head end, a hexagonal arrangement of small mandibles around a maw presumably allowed it to chew through the ice that was its home as well as ingest whatever other organisms its diet consisted of. The rest of the body was narrower, as though adapted to slither through the passages it created for itself. At regular intervals along its length, small extrusions -- whether it was best to think of them as legs, tentacles, or antennae, Vikk wasn't sure -- emerged, again in a hexagonal pattern. After the last of these, the body became wider again, though still narrower than the head. Presumably the currently closed orifice in the centre of this was where it excreted from. There were also what looked like small organs arranged around the outside. Vikk speculated that these were some sort of analogy to scent glands, and imagined the creatures communicating with each other chemically as they followed each other through the ice.

This was the most complex lifeform she had encountered in many jumps. And yet it still seemed unlikely to be intelligent, though the time she had spent with the drifting dirigible creatures of Planet K, a gas giant, had taught her not to be so close-minded on that score.

It was as she was remembering that encounter that the large attention markers Interface was projecting on the upper part of her HUD finally had the desired effect.

She looked up to see that the creatures down on the ground had aligned themselves into primitive alphabetical glyphs. They squirmed around on the ground, so that the outlines of the letters constantly shifted slightly, as the creatures changed places with their neighbours, but the underlying shape of the message was clear.

WELCOME BACK ALANNA

* * *

_Propulsion Workshop, Jovian orbit_  
_Transcriptions: 0_

WELCOME BACK ALANNA

Vikk floated back from the banner hanging on the wall of the hangar. It still wasn't straight.

"You must be looking forward to seeing her again," Gar said as she made another attempt to adjust it.

The observation had almost certainly been prompted by his Interface's small talk module. His real attention must be almost completely centred on monitoring Alanna's final approach. It was the final braking phase that was in many ways the most dangerous, and it was Gar's subsystems that were responsible for ensuring it worked smoothly.

Vikk still tried to leave her Interface switched off as much as possible. "It feels strange, to think that from her point of view she's only been away for a few days." 

"You understand the equations better than any of the rest of us," Gar said. Now that was the authentic Gar. The last six months had felt longer to Vikk than any previous similar period in her life, in ways that were not at all related to the effects of relativistic time dilation. "Do you think she'll be annoyed?" he went on when she didn't respond. "That this test flight will be the only one the slip drive ever does?"

The flight had been an unqualified success. Alanna's long, constantly accelerating arc out to the Kuiper belt had followed all Vikk's projections perfectly. The biofeedback telemetry -- which had come at increasingly long intervals, until finally at maximum cruising speed Vikk had been able to watch a single one of Alanna's heartbeats stretch over minutes of her wallclock time -- showed that the gravity bubble had worked perfectly to insulate her from the effects of the outrageous acceleration the drive produced by exploiting the differentials between the affine connections of neighbouring branes. Proceeding straight to a crewed test flight hadn't just been about Vikk's confidence in her calculations, or Alanna's daredevil nature. The drive was supposed to open up the possibility of realistic human colonisation of the nearer parts of the galaxy. The biological problems of long term cryonics, and the societal problems associated with generation ships, had, in the end, both proven to be less tractable than the physics of NAFAL travel.

And yet, those same breakthroughs had led to an even better system. The Transcription Engine would be to the slip drive what the slip drive had been to the previous century's fusion rockets: with a few rearrangements of the gravitating masses, instead of simply gaining traction by interfacing with the bulk, the ship could punch straight through it and emerge at a far distant point in zero subjective time. Vikk knew that the popularisations were already calling it a "real life hyperdrive". Drone flights within the Jovian system had already proven successful and the human-rated version would be ready in a few weeks, as soon as the final micro black holes were created in the Propulsion Workshop's particle accelerator: the largest mankind had ever built, encircling Callisto completely. The first test flight was Alanna's for the taking, if she wanted it. Vikk wasn't entirely sure that she wanted her to want it. "Well, I'll have other things to discuss with her tonight," she said to Gar finally.

Gar began to laugh, but then broke off suddenly. The progress of the deceleration phase had caught his full attention. Immediately, Vikk called up her own Interface, watching the telemetry -- cascading in now at an absurd rate, as Alanna's frame of reference resynchronised with theirs. There was a small asymmetry in the output of the braking units: a misnomer really, as they were simply another set of drive units, set up to provide thrust in the opposite direction. But at the speeds at which Alanna was still travelling, even that could be disastrous, leaving her stranded dozens of AUs away at best. But the worst case scenario was the one that Vikk had spent night after night calculating how to avoid: if the gravity bubble which served as the inertial frame of reference for Alanna herself collapsed, the effects would be instantly and horribly lethal.

Neither of them spoke for long seconds, as Alanna streaked closer and closer. But then things evened out -- she must have noticed the imbalance and throttled back on the other engine. In Alanna's timeframe, it had been one of her famous lightning fast reflexes. But Vikk wondered why the automatic systems had not picked it up even faster. Even if the slip drive was never going to become the workhorse they had originally thought, understanding what had gone wrong would still be a useful exercise in better understanding the limitations of the systems. But worrying over the data and its implications could wait: her lover was finally back.

" _Zephyr_ to Workshop One," came Alanna's voice over the open channel. Just from the elated tone in her voice, Vikk could picture the broad grin on her face. "Did you miss me?"

* * *

_Planet X_  
_Transcriptions: 153_

Vikk stared at the message in shock.

The many implications cascaded through her brain immediately, Interface minimising itself -- it knew her well enough by now to realise that she would want to think this through for herself. These lifeforms _were_ intelligent, and capable of communication. But most significantly of all: Alanna had been here. And recently enough that they remembered her. Indeed, they thought Vikk _was_ her. For a moment, she thought it fair enough that the bulky spacesuit made them look alike. But there was no indication on the creature still resting on her glove of anything resembling a vision organ.

Before she had time to puzzle things through further, the creatures out on the ice squirmed into a new configuration:

WHY DO YOU NOT DANCE

Vikk laughed inside her helmet. Her earlier speculation that they were sensitive to vibrations seemed to be borne out. The mental picture of Alanna, encumbered by her spacesuit, jumping around on the ice, painstakingly teaching the creatures to understand the patterns of vibrations that arose from her movements, filled her with joy. Not only at its comic absurdity, but at the confirmation that not only had Alanna been here, she had still been her unique self.

"I'm not Alanna," she said to the creatures, uselessly. "And I'm sorry, I don't dance." She watched the creatures for a while longer, wondering if she should try something. But without knowing the codes Alanna had taught them -- the steps of the dance -- she risked confusing them further.

As she watched, she saw that new creatures were constantly burrowing up out of the ice, as others went back. She wondered if this was to allow each to spend time out on the surface without risking long-term damage from exposure to the cold, biting wind. Or was there something more to it than that? Were the returning creatures taking information back down through the ice? Was she dealing with some sort of hive mind? Or was there some completely other creature down below, capable of controlling the actions of these ones?

Eventually, they squirmed into a new configuration.

ARE YOU ANOTHER

So they had figured it out. But she still had no way to respond, until, a little while later, they rearranged themselves to spell:

LEFT YES RIGHT NO

Vikk jumped left, as hard as she could. Quietly, Interface highlighted a schematic of the suit itself with information about how long it could withstand such treatment.

The creatures did not respond immediately: a large number burrowed into the ice, making Vikk feel more confident in her hypothesis that some sort of chemical communication was going on, enabling them to decide how to respond to her. The response, when it came, involved even more creatures emerging, enabling them to spell out a somewhat longer message:

WE WILL TEACH YOU TO DANCE

* * *

_Propulsion Workshop_  
_Transcriptions: 0_

The party was in full swing. Everyone wanted to talk to Alanna, naturally enough, but her responses were tangential at best, a non-stop stream of consciousness that was partly due to the drugs she had taken to maintain awareness during the flight not having worn off yet, but mostly related to her natural enthusiasm for the thrilling experience she had just been through. Vikk hung on every word of it, nonetheless.

"It was amazing," Alanna was saying to Gar. "I can't describe it. Not just the thrill, the _beauty_. The stars were so _colourful_ , you have no idea. It was just like you said, Vikk." Vikk had indeed predicted that the extreme Doppler effect Alanna would observe would mean that she would be seeing the infrared spectra of the background stars blueshifted up into the visible range. "But you can all see it yourselves from the recordings. You really should. Oh, it was amazing."

This went on for some time, punctuated by effusive thanks to everyone for enabling her to experience it, but most of all Vikk, who had to submit -- not unwillingly -- to several ostentatious kisses.

When they finally reached the privacy of their quarters, Alanna's lovemaking was equally overspilling with enthusiasm. Vikk wanted nothing more than to cling on tight to her, but Alanna kept succeeding in wriggling away, to pounce on her from some new direction and stimulate her in some other way.

Finally, spent, they lay back, limbs entangled and heads resting on one another. Alanna seemed at last to have reached some sort of equilibrium. "So, did you miss me?" she asked.

"Every day," Vikk said.

"I didn't miss you," Alanna said.

Vikk affected an overexaggerated hurt tone of voice, to mask the fact that she did feel slighted. "I know it was only a few days for you, but ... not even a little bit?"

"No, because you were with me. It was your ship, your drive," Alanna said. "You're a genius. I mean, I know everyone here is a genius, apart from me--"

"No one else here could do the things you do," Vikk said insistently.

Alanna ignored her. "But everyone knows that this was your theory. And you did it all without even using your Interface to check your working as you went along."

"People exaggerate that sort of thing," Vikk said. "I used plenty of other tools."

Alanna picked up a strand of Vikk's hair that was lying across her chest and held it in front of her eyes, teasing apart the hairs and inspecting them one by one. "Why did you choose propulsion physics? You could have revolutionised any field out there."

Vikk laughed hollowly. "No, I couldn't. The number of areas with proven-intractable problems vastly outweighed the ones where research might still be fruitful long before I was born. I was never going to crack true AI, for example." Near-AI expert systems such as the ubiquitous Interfaces had been around for hundreds of years, but no one had ever managed to create something that didn't require the input of human thought somewhere in the process to produce genuinely useful results in novel situations. The fates of the AIs that had been attempted were still argued over by applied philosophers as to whether they indicated anything significant about the underlying nature of reality.

"You know some people think you're an AI, don't you?" Alanna said. "The one code that managed to bootstrap itself out of self-referential nonsense and yet not shut itself down completely, downloaded into an android body it secretly arranged to be constructed."

"You forgot the part where I'm a military experiment, lain dormant since ... whenever they last had militaries."

"Well, obviously, I know different," Alanna said. She dropped Vikk's hair and turned round to prop herself up on her elbow. "No AI could do the things you do to me."

"Oh, is that right?" Vikk rolled onto her side, to mirror Alanna's pose. "After all, if this hypothetical AI version of me were running such a good emulation of human behaviour in other respects ..."

"Well, if you put it like that, I can't be 100% sure," Alanna said. "Maybe you'd better provide me with a bit more evidence to evaluate."

"With pleasure."

* * *

_Planet X_  
_Transcriptions: 153_

Hours later, the hexworms -- Alanna's name for them, apparently, which they had adopted -- had taught Vikk the basics of the communication protocol Alanna had established with them. It was slow progress: it took at least five minutes for them to rearrange themselves each time, and that was when she made the response they had predicted to a relatively simple question. She was convinced now that there was some sort of huge colony of the creatures buried under the ice, and it was some sort of gestalt mind made up of the interactions of the hexworms themselves that she was communicating with -- there was a definite correlation between the number of worms which tunnelled back under the ice and the length of time it took for a response to form.

But she was jumping back and forth across the ice in ever more complex paths, across an imaginary pattern -- hexagonal, appropriately enough -- that she had allowed Interface to overlay on her visual field.

She was trying to work out how to establish their measurement of time: she wanted to ask how long ago Alanna had been here. After so long following her trail through the bulk, discovering concrete evidence of her presence had given her new hope.

The hexworms were rearranging themselves again, but she couldn't yet decipher what the message was going to be.

A soft chime noise sounded inside her helmet and Vikk instantly looked up -- if Interface was using an audio cue, it had to be a high priority, because it knew she hated those. The suit's status readouts indicated that it was running on reserve power: maintaining an appropriate temperature in the frigid conditions was taking its toll. She was trying to work out how to explain the situation to the hexworms when she saw the message:

DO YOU NOT NEED TO RECHARGE

"Well, if you both think so," Vikk muttered to herself, but even as she did she realised that this was an opening to discuss their awareness of time passing: they knew how long Alanna had been able to stay outside for at any one time. But that would have to wait.

She made one big jump left, and then paused before trudging back to the descent pod, deliberately taking a path that broke from the hexagonal grid she had spent the last several hours within, hoping to make clear that this was walking, not talking.

As soon as the suit was docked in its recharge station and she was through the airlock, the pod's Interface projected a holographic face and started chattering excitedly. "We -- that is, the siblings up there -- have found some very unusual things."

"Show me," Vikk said. If it had defaulted to this sort of user interaction, then it must have been truly overwhelmed with information, and it wasn't worth telling it off about it.

The pod's internal screen lit up with the spectroscopic analysis from the rock earlier. But there was far more beside: the shipboard Interface processes had decided to take detailed spectra of as many stars as they could. The ship's astrogation sensors were hardly designed for such work, but they could do it at a low efficiency.

All the spectra -- stellar and planetside -- were somehow ... oversimplified.

"Show me the Periodic Table," Vikk said. It flashed up, all nine periods displayed with Vikk's preferred annotations: the pleasing mathematical pattern of the half-lives of the isotopes in the island of stability caught her eye for a moment, as it always tended to, before she forced herself to focus. "Highlight all elements found in any of these spectra." Suddenly, most of the table went dark, the first three rows still brightly lit, the fourth suddenly stopping at iron. 

Vikk felt a creeping sense of something, but whether it was dread or awe she wasn't quite sure. "Analyse me," she said quietly.

"Repeat request."

"Do a spectroscopic analysis of some of my tissue."

A robotic arm unfolded itself seamlessly from a wall panel, a small needle at its tip. Vikk proferred her arm and felt it suddenly punch its way in by half a centimetre or so. As it withdrew, it flooded the region with anaesthetic and time-limited cellular regrowth promoters.

The arm folded back into the wall. "Working," Interface said.

"Human biochemistry just doesn't work without certain trace elements," Vikk said, thinking aloud. Interface made an affirmative noise, but she ignored it. "Many of them well beyond atomic number 26. So any biopsy should--"

"Results available," Interface said.

"Show me," Vikk said.

New pop ups appeared -- in amongst the spectroscopy was a health analysis that claimed that Vikk had elevated levels of some hormones, but was still in fine health overall.

"Add the new elements to the Periodic Table," Vikk said.

"I already thought of that," Interface said. "There are none."

"That's impossible."

"We know."

"Unless this isn't our brane at all."

* * *

_Callisto orbit_  
_Transcriptions: 0_

Black holes, even microscopic ones, could not be moved by conventional means. They had to be persuaded to follow the contours of space-time to the correct destination. The fact that the most efficient way to do this was to use other black holes had become a commonplace since Vikk had solved a particularly abstruse set of field equations, but the sight of the near-invisible ballet -- only visible by the occlusion of the distant stars by the singularities, and occasional flashes as dust grains and particles of the solar wind were assimilated -- still gave even her a chill.

The singularity ascending from the surface now, when finally, gently, placed into position within the Transcription Engine, would be the final stage of the construction of the _Endeavour_.

"It still doesn't look like a ship to me," Alanna said. They were watching from the shuttle that was bringing Alanna to the _Endeavour_.

Vikk could see what she meant: it was more a skeletal spherical framework built around the mutually orbiting black holes that made up the Engine, the size of a large asteroid or small moon. Their mutual gravitational interactions would leak into the bulk just sufficiently to punch a hole through it to another point on the brane. Real space distance became immaterial -- the only thing that mattered to the destination was the details of the interplay of the gravitating masses. Most of the space on board the ship was taken up with the computer systems that would manage the process minutely.

"Well, if you don't want to--"

"I didn't say that." She turned to Vikk with a sad smile. "I know you're worried, but you know me. To be the first human being to travel through the bulk ..."

"There are so many variables," Vikk said. "Just the tiniest miscalculation and you could end up in the Andromeda galaxy."

"Have you miscalculated?" Alanna said.

"No," Vikk said eventually. "But--"

"But nothing. When it comes down to it, it's very simple: I have confidence in you."

Vikk pulled her tight and kissed her. "I love you. Always."

"I'll be back within an hour," Alanna said. Vikk bit back the immediate response that came to mind about the realignment cycle actually being 73 minutes long. "Don't be so melodramatic."

The shuttle pilot came back from the cockpit. "We've docked with _Endeavour_ ," he said. "Whenever you're ready. And, er ... good luck."

"Happy landings," Alanna said to him with a grin.

Vikk walked with Alanna to the airlock, stealing one last kiss before she put on her helmet. "I love you," Alanna said, her voice muffled by the suit. "Always. Now get out of here before you get asphyxiated."

Vikk went back to the cockpit, and was relieved when Gar shushed the pilot in his attempt to talk to her. They watched together as the _Endeavour_ simply disappeared from real space, exactly as intended, Alanna's parting message -- a bad pun about how Vikk was the brains of the operation -- ringing in their ears.

For the next hour and a quarter, Vikk analysed all the available data from the transcription. All the detectable phenomena associated with it, from neutrino flux to the backwash of gravitational waves, were exactly in line with predictions.

But time wore on, and the _Endeavour_ didn't reappear. Vikk checked the data again. Still nothing appeared wrong.

Other shuttles flew across from the Workshop, until the space station had only the bare minimum skeleton crew, as nearly everyone joined Vikk in the hunt for answers, still optimistic that Alanna would reappear sooner rather than later. It was nearly a day before Gar was able to persuade her to take a break.

* * *

_Planet X_  
_Transcriptions: 153_

"It makes perfect sense," Vikk said. "Oh, what a fool was I."

Interface was silent.

"Look, you can use your audio outputs," she said. "Right now I wouldn't mind having someone to talk to, even if it's not really ... someone."

"I can use any number of appearance and voice settings," Interface said.

"Default is fine." Early on in the journey, Interface had even offered to appear as Alanna. Vikk hadn't tried to explain why she didn't want that, simply made it very clear that Interface should delete that suggestion permanently.

"You believe we are in a different brane," Interface prompted.

Vikk was pacing around the limited space of the pod. "Right. Neighbouring branes in the bulk, separated by Planck lengths in an unrolled higher dimension. I thought we could punch through the bulk and re-emerge in the same brane, but instead we were being transcribed into different branes each time."

"But the drone flights were successful," Interface put in.

Vikk considered the point, surprised that Interface was coming up with such useful input. "Could be to do with the range we were attempting, or the overall mass-scale of the Engine and the ship. Or perhaps someone in a neighbouring brane was sending their drones through at exactly the same time-- no, that can't be it. Coincidence can only go so far." She paced around a little more. "Different branes have different histories, at the very least, but could have different physical laws. _Do_ have different physical laws, from the looks of things. The further we get from our original brane, the more variation shows up. This universe must have some different configuration of its fundamental constants--"

"The charge on the electron, the fine structure constant, the gravitational constant," Interface started to list.

Vikk made a cease gesture. "Yes, yes. Some combination of small tweaks to one or more of those must have done something to the nucleosynthetic processes inside high mass stars," Vikk said. "So that nothing beyond iron ever forms. Perhaps the constants have been drifting with every transcription that we make ..."

"Is there any way to use archived data to determine that?" Interface said.

"Good question," Vikk said, stopping for a moment. "Really good question. But we can work on that later. The question is, how could we survive? My body and your systems both rely on trace amounts of heavier elements. And this entire universe must work radically differently on so many levels -- there'd be little to no naturally occurring radioactivity, for example. Somehow the transcription process itself must have rewritten us to fit the rules of this new universe."

"Is that possible?" Interface asked.

"Until just now, I would have said no." Vikk paused. "But ... we have the evidence of our existence here. So it must be."

"Is it guaranteed to take place in any transcription?"

"Who knows?" Vikk said irritably, before the consequences caught up to her. "We've been following Alanna's gravitational wave wake," she said. "But what if somewhere there's a boundary to the survivability of the process?" She _had_ to know how long ago Alanna had been here. "Is the suit recharged?"

"Suit power supply at 19%," Interface said.

"That's enough," Vikk said. "Prepare the airlock cycle."

She suited up as quickly as she could and headed out onto the ice. She still didn't know how to frame questions about time so that the hexworms would understand.

Only a few of the creatures were still on the surface, but the vibrations of her making her way over -- as quickly as she could, but still agonisingly slowly as she leaned into the everlasting wind -- brought many more out of their burrows.

They wriggled and squirmed their way into position.

THIS IS NOT YOUR UNIVERSE

"You _knew_?" Vikk said, at a loss for how to dance her shock.

More and more hexworms made their way out of the ammonia ice, spelling out more and more messages.

ANALYSE OUR GENETIC INFORMATION

It was then that she realised that a few of the hexworms were crawling up her legs and into the pouches on the suit.

WE DID NOT KNOW BEFORE

BUT NOW WE UNDERSTAND

WE ARE A MESSAGE BUT WE CANNOT ALWAYS READ OURSELVES

Now they were dissolving into nonsense, Vikk thought. But then again, she had just turned out to be wrong about some of the most fundamental assumptions she had made about her life's work. Making suppositions about alien creatures from another universe was probably not the best idea. She made the short sequence of jumps that denoted "I do not understand" -- the one she had become the most familiar with on her previous foray.

However, the hexworms settled into their usual squirming, interchanging patterns: it appeared that nothing new would be spelt out straight away. Eventually, however, they began to reconfigure:

WE DO NOT UNDERSTAND

Great, thought Vikk. Mutual incomprehension. But then the next rows of hexworms rearranged themselves:

THE MESSAGE FROM ALANNA

BUT WE PROMISED HER

THAT IT WOULD BE PASSED ON

VIKK FOLLOW YOUR HEART

* * *

_Propulsion Workshop_  
_Transcriptions: 0_

Gar walked in on Vikk in front of a huge holo volume showing the design specifications for the _Endurance_. "There are other people who could do this," he said when she gestured it to minimise.

"You can't stop me," Vikk said. "You know you can't. And you don't want to, not really."

"All right, then, there are other people who _should_ do this. People better qualified and ... less invested?"

"There might be better pilots," Vikk said. "But no one else who can try to figure out what went wrong with the Engine on the fly."

"You're sure she survived?"

"I know it, Gar," Vikk said fiercely. The _Endeavour_ had been an experimental vessel, but fully stocked with all the equipment a future exploration ship might require. It was easier to do that than to recalibrate all the calculations for future use -- even the smallest change in the mass balance would throw all the delicate calculations out of proportion.

"The data from when _Endeavour_ disappeared--"

"I'm not talking about the data from the _successful transcription_ ," Vikk said. "I _know_ she's still out there somewhere. And I'm going to find her."

"This isn't like you," Gar said.

"This is exactly like me," Vikk said. "What is it all the profiles about me say? That when I set myself a goal, I don't stop until I've achieved it?"

She watched as Gar floundered for what to say next.

"You should at least take someone else with you."

"Are you volunteering?" Vikk said. "Because even if you are, I wouldn't let you. I couldn't be responsible for Hahja feeling the way I feel right now. Besides, the ship is designed around a single occupant."

"Using their Interface heavily to interact with the systems."

"I'll get used to it," Vikk said. "Probably."

* * *

Endurance _, Orbiting Planet X_  
_Transcriptions: 153_

"They were an _archive_?" Vikk said. "Those creatures were ... designed?"

"Adapted, at least," Interface said. "They don't have DNA like yours, but they do have self-replicating molecules. And they do have 'junk' DNA. Not-DNA."

"Get to the point."

"It's _not_ junk," Interface said, bringing up a view of the "genome" it had sequenced from the hexworms that had offered themselves up. "Every last part of it that doesn't code for essential functions is a palimpsest, a history of the original sentient inhabitants of the planet, millions of years ago. They knew they wouldn't survive, when the tidal locking became complete. But they wanted to leave a record. So they created the hexworms, fitting them for the conditions that would exist in the future. Our scans of the surface now indicate that literally the entire twilight belt is one enormous colony, stretching kilometres deep. There are a few other organisms in the food chain, but they have no predators. Higher order cognition arises as an interaction of the chemical messages they leave along their paths through the ice. It took a fairly small subset of it to communicate with you. Obviously, the larger the scale, the slower the thought states."

"The planet is dreaming of its past."

"If you like. But there's more: the history goes right up to now. The genome is still being altered as time goes on."

"Does the record show when Alanna was here?"

"Two months ago, by our standards. She stayed for over a week."

"And would she have been able to work all this out?"

"With the help of my counterpart on _Endeavour_ , yes."

"But how did the hexworms know we were from another universe?"

"That's where things get interesting," Interface said. "They understood the existence of higher dimensions perfectly well, but apparently had no interest in exploring them in the physical sense. Mental models were quite sufficient for them."

"They turned their entire planet into one, I suppose," Vikk said. "This is _fascinating_. We could spend a lifetime on this information--"

"But you have to find Alanna for there to be a 'we'," Interface said.

"I meant--" Vikk stopped herself, shocked. "I meant you and me. But you're right, we do have to find Alanna. How many universes away is she by now?"

"We can't be certain how long she spent exploring after each stop," Interface said. Vikk had already calculated the upper bound by the time it added, "But at most, twelve hundred."

* * *

_The bulk_  
_Transcriptions: 154-1354_

Vikk punched the _Endurance_ through brane after brane, following Alanna's trail from one reality to another with more urgency than ever before. The laws of physics became increasingly divorced from the ones she had spent her entire lifetime studying, but still remained comprehensible. As the rules of the realities became weirder, the mystery of how she could continue to exist nagged away at her, and the concern that somewhere out there was a reality in which life couldn't exist -- one that Alanna might be on the verge of reaching -- drove her onwards.

Interface became more and more helpful, and they began to speculate that it was, after all, something about the nature of reality itself that imposed limits on AI. As they studied the speculations of the hexworms' ancient antecedents during the Transcription Engine's realignment cycles, Vikk and Interface slowly began to comprehend the significance of the aliens' mental mathematical models. The true underlying nature of reality was inherently mathematical, and mathematics could be apprehended. The Transcription Engine was far more than Vikk had ever realised, very different than she had envisaged: it transcribed _minds_ from one universe to another, fitting them into the rules of the new reality as best it could. They speculated that Interface's growing intelligence was a result of it adapting to those realities, or even to the process of travelling between them itself. And they speculated that the slow hexworm-mind of Planet X was somehow projecting itself into other branes all the time. Would they one day meet the hexworms again somewhere, in some unknowably different form?

As the realisations mounted up, the boundaries between Vikk, Interface, and the ship itself began to blur. Vikk, who had fiercely protected her independent identity all her life, finally surrendered to the idea that she could become _more_. They were three parts of a single whole -- the Engine, its management systems, and the pilot -- travelling across ever more bizarre realities. In one universe with a much faster speed of light, they shot in a sleek silver, streamlined body through the jets of an active galactic nucleus powered by a black hole with a mass greater than that of entire galaxy clusters in the universe where they had begun their journey.

And yet, there was still more to come. As the implications of their discoveries sank in, they realised that the bulk, and all its infinite branes, were but one of an infinite number of self-consistent systems which could be apprehended.

And still, they followed Alanna's trail wherever it led, driven on by the undying love that had started in one of their component parts roaring inside them. Had Alanna gone through a similar process, her mind opened by what she had learned on Planet X?

Until finally, Alanna's trail seemed to lead out of the bulk entirely. Activating the Engine to follow it was like an autonomic response by now, in this ever-changing, unthinkably strange body that somehow still maintained a mental process with a coherent memory stretching back all the way to one particular planet in one particular universe.

* * *

_The metaverse_  
_Transcriptions: 1355-∞_

Everything that can be true, is true. All self-consistent sets of axioms reify.

The entity that remembered being Vikk burst out of the axiom-set that described the reality of the infinite braneworld into a mind-shattering non-landscape of all mathematical possibility. A kaleidoscope of alternative frameworks for reality glittered and span all around. Some were gloriously complex, others deceptively simple. Over there, the endless generative possibility of eternal inflation, an entirely different single system that could contain everything the Vikk-entity had ever known. Hidden inside its structure, implicitly, was a copy of the braneworld it had emerged from, like a fractal. And there was the set of all fractals, beautiful but sterile. It was as though thinking about something brought it into the field of the entity's attention. It was no longer adequate to label it as sight, or any other sense -- the entity experienced its surroundings through pure contemplation of their existence.

Simpler geometries existed too, and these surely were finally too simple to support life. Pure Euclidean geometry existed in this realm, but so too did an infinite number of variations upon it, depending on what other axioms were added. Some of these did seem to somehow support life-forms of a kind, though there was something almost hellish about the simplicity of their existences.

There was no space, no time between these different realms; they simply existed. And yet, the Vikk-entity realised as it took stock, there was somehow still _change_ within this metaverse. Alanna's trail still led somewhere, in some meaningful way.

Even as it followed, still driven onwards by love, it took an immeasurable interval for the Vikk-entity to realise what was happening. As the bulk was to individual branes, so too was there a larger order to this realm of realms. Inconsistent sets of axioms _also_ reified; indeed, the infinity of inconsistent impossibilities was of a higher order than that of the axiom-sets which were stable. But the inconsistent ones were unsustainable, breaking apart under their own contradictions before reforming in new combinations. Occasionally, these would give rise to a tiny new consistent axiom set that had always been there, like a crystal forming from a cooling solution. It was these sorts of processes that gave rise to what the Vikk-entity decided to call metatime. As it assimilated this concept, the Vikk-entity grasped that its own existence relied on these same processes: it was a creature of impossibility, now, its thoughts imposing themselves on axiom sets that could support them, but always moving on to another before they could decay. Its existence and its trajectory through the metaverse were one and the same. And with that realisation came the knowledge that so too must it be for Alanna as well, or whatever entity had succeeded and encompassed her.

The Vikk-entity's trajectory wrapped around that of the Alanna-entity, both originating from the same single universe that here was a tiny point-within-a-point-within-a-point, and it was the embrace of lovers. Their ever-delayed reunion was and always had been happening, since the moment Vikk had first engaged the Transcription Engine to follow her lover into the unknown.

After another unknowable interval basking in the joy of having found one another once again -- of having always been together, here in this realm -- they became aware of other entities here: an infinite number of them, of course, originating in all the different ways it was possible for entities to reach this realm. The two entities had emerged here as consequences of the giddy thrill of exploration for its own sake, and an undying love. But there were other routes: pure contemplation, utterly unbridled ambition, or sheer determination to survive.

Each and every entity was in constant motion, for to remain still was to invite dissolution. But they noticed that one particular trajectory-body seemed to prefer to coil itself around various sixfold symmetries, from honeycomb infinite hexagonal tessellations to Calabi-Yau manifolds with six spatial dimensions. They approached, and it quite deliberately stepped itself through its axioms in ways that they both recognised as the dance that Alanna had taught the hexworms, and they had taught to Vikk. Was this the dreaming mind of Planet X, projecting itself out into the mathematical realm? Or the hexworms' distant designer-ancestors? It was impossible to tell; perhaps there was no difference. They danced their respects and moved on.

Eventually, the Vikk-entity and the Alanna-entity thought of their human components' original bodies, and so, instantaneously and always, they had them, as abstractions made of axioms: blood made of axioms pumped by incompleteness-theorem hearts. They drew one another close, and whispered back and forth to one another on a breeze of concepts:

"I love you. Always."

**Author's Note:**

> There are a large number of inspirations for various aspects of this story, but while editing it became obvious to me that the hexworms have some quite specific antecedents that I ought to acknowledge: they get half of their not-DNA from the Alastair Reynolds short story "Glacial", and the other half from the mind worms in Sid Meier's Alpha Centauri. And the final section owes a very large debt to (and doubtless takes terrible liberties with) [Max Tegmark's multiverse ideas](http://space.mit.edu/home/tegmark/crazy.html).


End file.
